1. Field of the Invention
The present invention relates to portable tools in general and, in particular, to extension bars used between the driving element of a portable tool and the driven element to extend the reach of the driving element and/or to provide illumination of the area about the driven element.
2. Description of the Prior Art
Extension bars which are used between a driving element of a portable tool and the driven element to extend the reach of the driving element and illuminate the driven element are known in the art, and are illustrated, for example, in U.S. Pat. No. 4,253,134, issued Feb. 24, 1981 to H. T. Barnaby, and in U.S. Pat. No. 5,477,434, issued Dec. 19, 1995 to D. D. Reed. The devices shown in each of these patents utilize a structure in which the light provided by the extension bar passes longitudinally through the bar end which engages the element to be driven, so that the area around the driven element is not illuminated during the driving operation. Also, in each of these devices, the illumination is continuous so long as the extension bar engages the driving element, thereby unnecessarily shortening the life of the battery or batteries used to provide the electrical power source for the illumination.
A device adapted to be temporarily attached around the shank of a screwdriver blade, a drill bit or a drive bar extension so as to be operable to selectively illuminate a work surface, but not extend the reach of the driver element is shown in U.S. Pat. No. 4,480,295, issued Oct. 30, 1984 to F. J. Shuster.